More than half of the states in the US have joined together in an unprecedented lawsuit against Meta that goes to trial on Tuesday, accusing the parent company of Instagram and Facebook of deliberately designing addictive products that lured in young people and caused them harm.

The jury trial is taking place in federal court in Oakland, California, and is expected to last between six and eight weeks. The jury is expected to hear from Meta CEO Mark Zuckerberg, Instagram CEO Adam Mosseri and employee turned whistleblower Arturo Béjar.

“Meta designed a dangerous product for young users, knew it to be dangerous, and then lied to children, families and the community about how dangerous it was,” said Rob Bonta, California’s attorney general. The trial proceedings will be led by attorneys representing California, Colorado, Kentucky and New Jersey, though the suit was filed by all 29 states in what is known as multidistrict litigation.

The 233-page lawsuit, first filed in October 2023, alleges that Meta regularly collects data on children under the age of 13 without parental permission in violation of federal and state laws. The lawmakers claim in court documents that Meta “refuses to abandon its use of known harmful features” and that its motives are based solely on profit to “maximize its financial gains”.

The sweeping legal proceedings could have profound consequences for the social media company. The attorneys general say that if Meta is found liable, damages could be as high as $200bn – an amount equivalent to the company’s 2025 annual revenue. The lawmakers are also asking that Meta be compelled to change the design of its products to make them safer for children, which may have longer-term effects than a fine.

Meta denies all allegations and says: “Rather than sticking to the facts or the law, the states have instead decided to chase an outlandish payout.

“The State AGs may call this a landmark case, but their limited claims are unsubstantiated and their financial demands are vastly disproportionate,” the company said in a statement. “The AGs offer no proof anyone in their states was misled, claim benign features like having an additional Instagram account somehow harmed their residents, and attempt to penalize Meta for industry-wide challenges like age verification.”

The attorneys general also say Meta “developed and refined a set of psychologically manipulative” features designed to maximize people’s time on its apps. Those include an infinite scrolling recommendation algorithm, constant notification alerts, thumbs-up “likes”, and visual filters for altering one’s image.

The lawmakers say young people are especially vulnerable to falling prey to such features and that excessive time online can lead to increased depression, anxiety, eating disorders and other mental health issues.

Internal research conducted by Meta is expected to be presented at the trial, including, for instance, a survey of 2,500 teens conducted in 2019.

“Young people are acutely aware that Instagram can be bad for their mental health, yet are compelled to spend time on the app for fear of missing out on cultural and social trends,” the results read.

Mounting lawsuits

The federal trial comes just two weeks after a judge ordered Meta to pay $567m to New Mexico in a similar case brought by the state’s attorney general. This was the second court-ordered financial penalty for Meta in New Mexico, bringing the total it is responsible for paying the state to $942m. A state trial in Tennessee is now under way

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Families, school districts and other attorneys general have brought thousands of lawsuits against Meta and other social media companies in recent years. The plaintiffs hope a death-by-a-thousand-cuts legal strategy will induce Meta to change its social networks for the better.

In California, thousands of coordinated cases have been filed in state court against Meta, YouTube, TikTok and Snap. Meta and YouTube lost the first of those cases to go to trial in February, being ordered to pay $6m to the young woman who brought the suit. (TikTok and Snap settled before the case went to trial.) Two more lawsuits slated to go to trial this summer, one federal and one in California state court, also settled for undisclosed sums.

The lawsuits have borrowed from the legal approach used against tobacco companies in the 1990s, which focused on cigarettes’ addictive qualities and the makers’ knowledge that their products caused harm and resulted in a $200bn in 1998 and enforced changes to cigarettes’ marketing.

Russell Coleman, the attorney general of Kentucky, said he and his colleagues are using that strategy and aim to show the jury that “Meta concealed what it knew about the harm its products cause young people”.

“AGs are in the perfect position to get this done,” he added. “We did it with the tobacco settlement in the 1990s. We did it with the companies behind the opioid crisis. We’ll do it again with Meta.”